Phylum Cnidaria is a Phylum of Kingdom Animalia. The defining characteristics of Phylum Cnidaria are that all organisms of Phylum Cnidaria are aquatic. Organisms of Phylum Cnidaria have a radial, as opposed to bilateral, symmetry and true tissues, but do not have actual organs. Another defining characteristic to Phylum Cnidaria is the presence of a Cnidocyte. Organisms of Phylum Cnidaria often reproduce asexually, but can reproduce sexually. An example of organisms of Phylum Cnidaria is Pelagia noctiluca